Today, I found out why my thesis supervisor made me change my whole project I was working on for the past 3 months. Apparently, he had another student doing the same thing and they published it today. FML

Op here, it turned out that this other guy was working on it before me (under the same supervisor..) so he rightfully published it. in the end I kind of resumed his thesis and continued best I could. It sucked, but I really want to graduate!

Three months is actually probably not the longer time to have been working on a project in some subjects, I'd say the other person probably had been working on it longer. It's really not okay for the supervisor to have given OP the project work while someone else was already working on it since this was likely to happen in the long run. I'm sorry OP, FYL indeed.

If a thesis was just published while OP was still working on theirs, odds are the other person had started way before the OP, possibly months to years before, which could explain why the supervisor forgot the topic was assigned a long time ago

Op here, it turned out that this other guy was working on it before me (under the same supervisor..) so he rightfully published it. in the end I kind of resumed his thesis and continued best I could. It sucked, but I really want to graduate!

hey! it's not a problem to have the same topic, but doing a (too similar) research is not accepted. Even when you're not aware of it. By the way, thank you all for the kind responses! I was really in a bad place after getting the news that my research was being invalidated, now I'm almost done!